1. Field of the Invention
The invention relates to an apparatus for disintegrating a calculus in a human body.
2. Description of Pertinent Information
Devices for disintegrating a calculus in a human body comprise a shock wave generation chamber having an inner surface formed in the shape of a pseudo-ellipsoid of revolution. The pseudo-ellipsoid of revolution has two foci. As a result, a shock generated at one focus will be concentrated at the other focus.
In order to use the device, a patient is immersed in a tank filled with liquid. The tank is brought into contact with an open portion of the shock wave generation chamber so that the chamber is filled with the liquid. A shock wave is generated, for example, by a spark discharge, at the first focus of the pseudo-ellipsoid of revolution. Before this spark is generated, the patient is so positioned so that the calculus in the patient is positioned at the second focus of the pseudo-ellipsoid of revolution. As a result, when the shock wave is generated, the calculus is broken by the shock wave.
This conventional device has several advantages. First, the calculus can be broken without any physical or mental pain being produced in the patient. Second, a long stay for treatment in the hospital is not required, inasmuch as this treatment takes a relatively short amount of time. However, because a liquid filled tank for immersion of the patient is required, the apparatus must be large in size and cannot be transported easily. Additionally, this apparatus is inconvenient because if a patient has a skin eczema, an external injury, or similar problem, the patient cannot be immersed in the liquid filled tank for treatment until the patient has recovered.
Thus, there is a need for an apparatus that disintegrates a calculus in the human body that is small, can be easily transported, and does not require immersion of the patient in a liquid.